With an increase in demand for communication, a high-speed optical transmission scheme has been standardized. For example, the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) recommendation G.709 defines a scheme of an Optical Transport Network (OTN) operating at about 1.25 to 100 Gbps.
Optical transmission in the OTN is performed such that a plurality of client signals is accommodated in an optical signal in a format called an Optical channel Transport Unit (OTU) frame, so that transmission of data having large capacity may be performed. As the client signal that is accommodated in the OTU frame, there are a Synchronous Digital Hierarchy (SDH) frame, a Synchronous Optical NETwork (SONET) frame, and an Ethernet (registered trademark) frame.
The client signals are respectively accommodated for Optical Data Units (ODU) that are multiplexed in the OTU frame. The bandwidth type of the ODU is defined by “ODUk” (k=0, 1, . . . ). For example, an ODU0 is a unit of data of 1.25 Gbps, and an ODU1 is a unit of data of 2.5 Gbps, and an ODU2 is a unit of data of 10 Gbps.
The OTN technology achieves transmission of data having large capacity in the unit of the ODU, so that contents such as a video and music may be provided to a user with high quality and multi-channel when the OTN technology is applied to a broadcast distribution system.
Regarding the broadcast distribution technology, for example, Japanese Laid-open Patent Publication No. 10-294729 discloses a connection procedure that is used to find by rearrangement a path for multirate/multicast traffic through an SDH cross-connect with sub-network connection protection. In addition, Japanese Laid-open Patent Publication No. 2005-192213 discloses a network-based data distribution scheme in which data to be distributed to a plurality of destination links is replicated in a physical layer in a network-based communication system.